Tilting furnace



2 Sheets-Sheei l INVENTOR J. E. M DONALD TILTING FURNACE Filed Oct. 31, 1935 June 16, '1936.

June 16, 1936. J. E. M DONALD TILTING FURNACE 1935 2 Sheets-Sheet 2 Filed Oct. 51

COO 0000 0000 00000 @0000 OOOOO 00 gNVENTOR M of other uses.

Patented June 16, 1936 UNITED "STATES PATENT OFFICE TILTING FURNACE James E. MacDonald, Pittsburgh, Pa.

Application October 31, 1935, Serial No. 47,664

4 Claims. (01. 26346) My invention relates to furnaces and more particularly to interior corner constructions of open hearth furnaces-of the tilting type, although certain features of the invention are susceptible The bodies of tilting. open hearth furnaces are frequently fifty feet in length and'twenty-two feet wide, with front and back walls each approximately two feet thick. In order to provide for proper inflow of combustible gas and air mixtures and outflow of gases through end ports which are necessarily of reduced area relative to the interior cross-sectional area of the furnace, the interior corners of the furnace at each end have to befilled in with fire brick or other refractory material, so that there will be a gradual expansion of the incoming combustible mixture and reasonably free flow of the waste gas from the furnace.

In tilting the furnace to discharge the molten metal into ladies at the rear side of the furnace,

the front side of the furnace must, of course, be

raised, with the result that frequently the brick ,work at the front comers of the furnace falls into the melting hearth. Even if means are provided for preventing the corner brick structure as a whole from falling into the furnace, quite frequently some of the bricks fall out of place, owing to the breaking or pulling loose of the exposed bricks from the other bricks, by reason of the wide differences in temperatures'as between the exposed bricks and those bricks which abut against the framework of the furnace. 1 As a result, melting operations have to be suspended frequently in order to make the necessary repairs at the corners, besides which difliculty is experienced in removing fallen bricks from the molten bath.

My invention has for one of its objects the provision of corner brickwork of such form that notwithstanding breaking and loosening of the bricks through temperature changes or for other reasons, they will nevertheless be so completely interlocked with one another that danger of bricks or parts of bricks falling away is reduced to a minimum.

Another object of my invention is to provide brickwork having individual tiles or bricks so formed that they may all be substantially duplicate in form and size, and can at the'same time be adequately interlocked with one another.

Some of the forms which my invention may take is shown in the accompanying drawings wherein Figure 1 is a horizontal cross-sectional view through a tilting open-hearth furnace; Fig. 2 is a view taken on the line 11-11 of Fig. 1; Fig. 3 is a view taken on the line III]II of Fig. 2; Fig. 4 is a view taken on the line IVIV of Fig. 3, the arrangement of courses shown in Figs. 2 and 4 alternating in order to more completely interlock 5 the bricks; Fig. 5 is a view taken on the line V--V being rocked to tilt the furnace, by suitable operating mechanism [2 whenever it is desired to fill ladies from the spout' l3. These parts may be of conventional form. Also, the furnaces have their melting hearths or bottoms l4 formed of magnesite or other suitable material, the magnesite sloping upwardly toward the sides and ends of the furnace to a plane above the metal level.

At each end, the furnace is provided with a 'port l5. These ports serve as inlet and discharge openings for the gas and air mixture and the exhaust gases, respectively.

As heretofore indicated, the corners of the furnace adjacent to these ports must be so filled in with brickwork and the like as to form an orifice which will properly take care of the gradual expansion and contraction of the gas stream in entering and leaving the furnace, otherwise proper expansion and burning of the incoming combustible mixture will not be had and there would be interference with flow of exhaust gases from the furnace. The falling away of even a few of the corner bricks may seriously interfere with gas flow.

The rear corners of the furnace at each end thereof are as indicated at 16. These corner structures l6 need not necessarily be constructed according to my invention, since the tilting of the furnace is principally in the direction indicated by the arrow in Fig. 1, to discharge the molten metal into ladles. However, the corner structure It may conveniently be formed in the same manner as the corners at the front side of the furnace, as hereinafter described.

The furnace is provided with the usual metal framework, including corner post members I! and I8, and a skewback channel I9. The magnesite material i4 is usually extended up at the sides and ends, so as to slope downwardly away from the melting zone, as shown in Figs. 1 and 3, thus reducing the tendency of the corner brickwork to fall into the furnace when the furn'ace is tilted. However, it has been practically impossible to dispense with the brickwork or to make said slope of such angularity as to eliminate the falling of the bricks into the furnace, when they become loosened.

The bricks which I employ are of the form shown more clearly in Figs. 6,7 and 8 Each brick 2| is provided with bosses or protuberances 2| that may be of circular or other shape, and with recesses 22, that are preferably of the same contour as the bosses 2|, but which are preferably somewhat larger than the bosses in order to allow for s ight expansive and contractive movements of the bricks relative to one another, without rupturing. For example, if the bosses 2| are four inches in diameter, the recesses 22 may be of 4% inches or 4%inches in diameter.

Assuming that the bricks are 18 inches long and 9 inches wide, the centers. of the protuberances 2| and the recesses 22 will each be 4 /2 inches from the sides of the brick and from the adjacent end thereof. bejl inches from the midpoint of the brick. By reason of this arrangement, the bricks of one course can be laidcrosswise of the bricks of another course, as indicated for example, in Figs. 2 and 4, which show adjacent courses of bricks, and there will therefore be effective interlocking between the bricks of each course, and the outer-,

most brick of each course will through interconnection with intermediate bricks have connection with the rearmost brick of each course.

By the arrangement just described, all of the bricks of a corner structure are securely bound together as a unit, except for the slight expansion and contraction which is provided for through the clearance between the protuberances 2| and the recesses 22, and there can consequently be no falling away of substantial portions of the brickwork into the melting hearth.

Whileinsomecasesitmaynotbenecessary to anchor the brick work as a whole to the framework of the furnace, as for example, where theslopeattheupper edges ofthete hearth is very great, I prefer to provide anchors for holding the brickwork in place. These anchors are shown more clearly in Fig. 5, and may suitably consist of strips 24 of sheet metal, the inner ends of which are bent up and welded to the metal post member II, and the outer ends of which are bent laterally to engage the outer ends of certain bricks, or connected in any other suitable manner. The strips are of rather thin metal so asnot to interfere with the proper laying up of the bricks, and will have a sufliciently long life, since they are protected from excessive heat by the bricks which are adjacent to the inner faces of the corners.

Certain of the bricks which extend beyond the metal corner posts I! as shown in Figs. 2 and 3, are further anchored by wedging or keying them to the skew backs 25.

the adjacent :courses of bricks.

Also, such centers will Referring to. Fig. 9, I provide bricks 21 and 28 of the same dimensional form as the bricks 20. The bricks 21 on their upper and lower faces are provided with longitudinally-extending corrugations or ribs 29. The corresponding faces of the bricks 28 are likewise provided with corrugationsor ribs 30, but they extend transversely of the bricks.

In laying up the bricks, the bricks 28, of course,-are disposed transversely or crosswise of the bricks 21, and their corrugated or ribbed faces interflt with the corresponding faces of The bricks 28 are positioned to overlie two of the bricks 21 and thereby effect interlocking of the brickwork.

The ribs on one face of the bricks are preferably formed slightly larger than the ribs on the opposite face thereof, so that the interlocking facespf the coursesof brick fit somewhat loosely, to permit expansion and contraction thereof without rupture.

I claim as my invention:-

l. A tilting furnace having an interior corner structure comprising bricks each having offsets formed in the upper and lower faces thereof, the ofisets being so positioned that those in each course of bricks have interspersed, but laterally spaced relation with the ofisets of an adjacent course, whereby relative shifting movement of the courses is restricted, the structure being of 30 a width exceeding the total length of a plurality of bricks.

2. A tilting furnace having a bottom wall which near one of its edges slopes downwardly, in a direction away from the furnace chamber, a corner structure built on said sloping surface, and composed of courses of bricks that have lostmotion interlocking engagement with one another which limits relative movement of the 1 bricks in one course with respect to the bricks of an adjacent course.

3. A tilting furnace having a bottom wall which near one of its edges slopes downwardly in a direction away from the furnace chamber, a corner structure built on said sloping surface, and composed of courses of bricks that have interlocking engagement with one another, and a. roof element having engagement with the topmost course of bricks.

4. A tilting furnace having a bottom wall which near one of its edges slopes downwardly in a direction away from the furnace chamber, a corner structure built on said sloping surface, and composed of courses of bricks that have interlocking engagement with one another, and a roof element having engagement with the topmost course of bricks, the corner structure being of a width exceeding the total length of a plurality of bricks.

JAMES E. MACDONALD. 

